Mapping temperature-sensitive mutants of vesicular stomatitis virus by RNA heteroduplex formation

Duplex RNA molecules made by hybridization of virion and mRNA of vesicular stomatitis virus (VSV) were digested with ribonuclease and separated into five size classes, each containing the gene and the mRNA for one of the VSV proteins. Denaturation of the duplexes yielded full size mRNA lacking poly(A) tails. Utilizing duplex formation between the RNAs from VSV temperature-sensitive (ts) mutants and their revertants and subsequent RNase digestion under varying salt conditions, specific cleavages within a certain duplex were seen for representative mutants from complementation groups, III, IV and V. Specific cleavages were not seen for a group II mutant. From these results gene assignments cannot be made for group II; equivocal assignments are made for group III and clear assignments made for group IV and V. The assignment for the group V mutants, however, does not conform to expectations. Nevertheless, from these studies and other published ones, there is the suggestion that interactions may exist between the gene products of complementation groups II and V during VSV transcription and morphogenesis. These results also support the lack of transcriptional splicing for VSV mRNAs.